I am a Managing Partner at Brookside Strategies, LLC, an energy and utility management consulting firm based in Darien, Connecticut. I've spilled blood, sweat and tears grappling with the full spectrum of barriers and misconceptions about distributed generation and energy-efficiency technologies. Previously, I practiced law in New York City at Paul Weiss Rifkind Garrison & Wharton, LLP and Jenner & Block, LLP. I also attended journalism school at Columbia University and earned a JD at Stanford Law School. I've written about energy and environmental issues for Forbes, The Nation, Mother Jones and several other publications. I am the Chair of the Northeast Clean Heat and Power Initiative. Drop me a line - or two - at wmp@cleanbeta.com.

The Case for Climate-Change Alarmism

For better or worse, uncertainty pervades projections of global warming. Historically, this uncertainty has eroded support for implementing climate-change policies, but that may soon change – and dramatically so.

This may seem counter-intuitive, but only if you haven’t heard of climate-change’s “fat tail.” To put the significance of this fat tail in perspective, the “probability distribution representing the uncertainty in expected climate change implies that the risk of catastrophic outcome is more than forty thousand times more probable than that from an asteroid collision with the earth,” according to a recent report, “A Deeper Look at Climate Change and National Security,” by researchers at Sandia National Laboratory in New Mexico.

The climate system consists of several sub-systems, including the hydrosphere, the biosphere, the atmosphere, the geosphere and human systems. In turn, each of these sub-systems encompasses separate components, which include distinct elements and so on and so forth. The climate’s behavior reflects the collective interactions of these systems and sub-systems, but not always in a linear manner.

The so-called “butterfly effect” is a popular metaphor for explaining the chaotic behavior of complex systems like the Earth’s climate. A butterfly flapping its wings in Asia creates a tropical storm in the Atlantic Ocean a few weeks later. In complex systems, the slightest variation in initial conditions can create large deviations in future system conditions over time and not necessarily in predictable ways.

This non-linear tendency is why complex systems are more likely to follow a power-law probability distribution than the more familiar bell-curve distribution. In the former scenario, the tail of the distribution thins out more slowly in the power law scenario than it does in the normal distribution.

In a bell-curve distribution of probabilities, the range of possible events are clumped together around the average. Extreme outcomes fall on the margins and their likelihood of occurring fades away quickly. In a bell curve, the median and mean are the same. By contrast, in fat-tailed distributions, the median is extremely small compared to the mean, meaning that the probability of infrequent events is enormous.

This has vast implications for how we manage the potential risks posed by climate change. Simply put, “the planetary welfare effect of climate changes . . . implies a non-negligible probability of worldwide catastrophe,” according to Martin Weitzman, a professor of economics at Harvard University and a pioneer of the so-called “Dismal Theorem.”

Climate change’s fat tail makes the likelihood of rare events more so. The distinguishing feature of a power law distribution is “not only that there are many small events but that the numerous tiny events coexist with a few very large ones,” according to Albert-Lászlí Barabási, a physicist at the University of Notre Dame and author of Linked: The New Science Of Networks. Barabási explains: “If the heights of an imaginary planet’s inhabitants followed a power law distribution, most creatures would be really short . . . [but] nobody would be surprised to see occasionally a hundred-foot-tall monster walking down the street.”

So what are the policy implications of these non-negligible risks of catastrophic climate change? Reducing greenhouse-gas emissions not only makes eminently good sense, but may be the only realistic option for avoiding dangerous climate change. Carolyn Kousky, an economist at Resources for the Future, has explained that:

Traditional responses to the risk of extreme events are of limited value in mitigating risks of a mega-catastrophe. The underlying changes in the climatic system could not be reversed over any time scale relevant for decision-makers, limiting the efficacy of traditional recovery measures. Insurance markets will not function for these risks as they violate three key conditions of insurability: independent and identical losses, feasible premiums, and determinability of losses. Impacts could be difficult to smooth over time, even for governments.

Uncertainty is intrinsic to complex systems like Earth’s climate, but in the context of catastrophic climate change, this uncertainty is so severe that it is difficult to draw basic conclusions about how fat the fat tail is. According to Weitzman, it “is difficult to infer (or even to model accurately) the probabilities of events far outside the usual range of experience.”

Indeed, ”[r]ather than justifying a lack of response to climate change, the emphasis on uncertainty enlarges the risk and reinforces the responsibility for pursuing successful long-term mitigation policy,” according to a 2010 analysis by researchers at Sandia National Laboratory.

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@economart, Over the next century, the chances of a greenhouse-gas induced global catastrophe are hundreds of times greater than the estimated chance of a large asteroid crashing into the planet, according to estimates by researchers at Sandia. The U.S. actively pursues programs to mitigate the risk from a catastrophic asteroid encounter.

Sorry William, but the science behind the claim is ridiculous. Water is the pre-eminent greenhouse gas and we have little control over its atmospheric content.

And if greenhouse gases really do trap heat, then why is the moon, which receives the same measure of sunlight as the earth and which doesn’t have an atmosphere, always so much warmer than the earth in sunlight?

@economart, Your reference to water vapor makes me think you’re missing the point. The climate is like an engineered system. By way of analogy, imagine the climate worked like a fixed-wing aircraft, which is designed to be stable when operated within certain specified conditions.

Fixed-wing aircraft provide a familiar example of engineered dynamic stability. A slight displacement of the control surfaces of properly trimmed airplane will generate forces and moments that tend to restore the original flight condition. When an aircraft is flown “outside the envelope” of its specifications it can become unstable. Nonlinear effects can take over, and the small negative feedbacks that served to stabilize the aircraft can be replaced with strong positive feedbacks that lead to abrupt or erratic changes in attitude. This can force the aircraft into a chaotic state, or a different self-sustaining state—such as a flat spin—from which recovery to safe flight may be impossible.

A stable aircraft will oscillate when perturbed from straight and level flight, because of the tendency of aerodynamic restoring forces to overshoot. The phugoid “porpoising” oscillation is the most familiar. Because the system is damped, the amplitude of the oscillations will decrease, returning the aircraft to a stable trajectory unless an inexperienced pilot over-corrects in phase with the oscillations, inadvertently amplifying them.

Because an aircraft has fixed characteristics (e.g. weight, airfoil shape, center of mass), and few degrees of freedom, it is straightforward to predict its future state. The climate system is analogous to an aircraft whose characteristics change as a function of time, airspeed, attitude, and altitude, in a nonlinear, coupled, irreversible, and incompletely known way. Such an aircraft might be capable of straight and level flight for an extended period of time. Any stability is perilous at best, and might be completely illusory. Moreover, any expectation that complete prediction of its future state would be misplaced.

——–” And if greenhouse gases really do trap heat, then why is the moon, which receives the same measure of sunlight as the earth and which doesn’t have an atmosphere, always so much warmer than the earth in sunlight?”—–

Because the moon does not have any atmosphere to trap the heat and move it around somewhere else before it strikes the surface.

It is called conduction and convection. It is what drives weather systems. Weather is the effect of the dissipation of solar energy within the atmosphere.

The earth has been around for a long long time. It has faced far greater amounts of CO2 in the atmosphere, and survived. The earth has been bombarded by all sorts of foreign materials and projectiles, and it survived. It has endured enormous internal stresses and natural phenomena, and survived.

Now it is expected that a few extra ppm of CO2 in the atmosphere will bring about some catastrophe from which earth and life shall never recover.

I have yet to see any evidence of this approaching or unfolding disaster. The temperatures on earth are very stable with little variation. The seas are rising by miniscule amounts and in orderly manner. They will not engulf continents or islands. I do not see increasing numbers of droughts or hurricanes or any surface disturbances. The increases in CO2 in the atmosphere have been small and orderly, not geometric.

Every threat identified by the IPCC has been retracted.

Where exactly is the turbulence or threat created by operating outside of this so called temperate zone?